MICROCYSTIN-LR ADSORPTION BY POWDERED ACTIVATED CARBON

The adsorption of microcystin-LR by eight different powdered activated carbons (PACs) was investigated and found to vary markedly between carbons. Wood-based carbons were clearly the most effective microcystin-1R adsorbents followed by coal-based PACs. Coconut and peat moss-based carbons were the poorest microcystin-LR adsorbents. The extent of adsorption for each PAC was related to the volume of mesopores (diameters between 2.0 and 50 nm) which was dependent on the starting material. Surface characteristics, however, were not related to the starting material. Competitive adsorption with natural organics in River Murray water significantly reduced the initial rate of microcystin-1R adsorption. There was also a considerable reduction in the maximum level of microcystin-LR adsorption, the extent of which was dependent on the type of carbon.